Signaling system



Dec. 9, 4- 1,518,682

W. R. G. BAKER SIGNALING SYSTEM Filed Nov. 6, 1923 Irn/enbor: WQILeT RG-BaK 3 His Atnorn e5.

Patented Dec. 9, 1924.

. UNITED STATES PATENT OFFlCE.

WALTER R. BAKER, OF SCHENECTADY, NEW YORK, ASSIGNOR T0 GENERAL ELEC- TR-1C COMPANY, A CORPORATION O'F NEW YORK.

SIGNALING SYSTEM;

Application filed'November 6, 1923.

To all whom it only canoe 2% Be it known that I, WALTER R. G. BAKER, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Signaling Systems, of which the following is a specificatio-n.

My present invention relates to means for transmitting high frequency signals, and particularly to the use of vacuum tube high frequency generators for this purpose.

lVhen vacuum tube high frequency gencraters are employed for signal transmission, particularly when considerable amounts power are used, it is desirable to keep the generator oscillating at all times, and not inte-rr ipt the production of oscillations during periods when no current is to be transmitted, as for example, between individual characters of a telegraphic signal. This effect is most ieadily brought about by supplying the oscillations generated to a storage or tank circuit, and supplying the radiating circuit from this storage circuit. The supply of high frequency oscillations to the radiating circuit may be controlled by detuning the storage circuit. When this is done, however, difliculty may arise by reason of the fact that the storage circuit is coupled to the radiating circuit and when the storage circuit is detuned the frequency of the oscillations produced will change to correspond to the resonant period of the combined circuits and oscillations will be radiated of this new frequency.

The object of my invention is to overcome this difficulty and to provide a means whereby the frequency of the oscillations generated will be. maintained constant in spite of the detuning of the storage circuit.

I accomplish the object of my invention by providing a connection between the oscillation generator and the radiating circuit whereby the frequency of the oscillations produced is determined almost entirely by the tuning of the radiating circuit. Preferably this effect is produced by providing a connection between the grid of the vacuum tube oscillator and the radiating circuit whereby the oscillator is excited entirely by means of the energy drawn from the radiating circuit.

The novel features which I believe to be characteristic of my invention are set forth Serial No. 673,180. 1 .l

with particularity in the appended claims, my invention itself however, both as to its organization and method of operation will best be understood by reference to the fol lowing description taken in connection with the accompanying drawing in which I have shown digrammatically one way ivliei'eb my inventionmay be carried into effect.

I have indicated in the drawing a threeelectrode vacuum tube 1, having the usual cathode 2, anode or plate 3, and grid 4. The plate circuit of this vacuum tube is supplied with energy from a direct current source 5 through a choking inductance 6 for preventing the high frequency oscillations produced from being short circuited through the source of power supply. Associated with the vacuum tube 1 is an oscillatory storage circuit comprising condensers 7 and variable inductance 8. A stopping condenser 9 prevents the direct current from flowing in the storage. circuit. High frequency energy is supplied from this storage circuit to a radiating antenna 10 which may be of the multiple tuned type having tuning coils 11 and 12, and as many more such coils, not indicated in the drawing, as may be desired. The energy is introduced into the antenna 10 through the tuning coil 11 by means of a coupling transformer 13, the secondary of which is connected to the coil 11 with a variable connection 14. The link circuit between the storage circuit and the radiating circuit is completed through the ground connections 15. This link circuit also includes an inductance 16 to which, by means of a variable connection 17, the grid 4 of the vacuum tube-is connected through the usual grid condenser 18, grid leak 19 and the series resistance 20. The detuning of the storage circuit is accomplished by coupling the circuit of the magnetic amplifier 2'1 thereto through a coupling transformer 22. The circuit of the magnetic amplifier may be controlled to bring about the desired detuning of the storage circuit by means of the telegraph key 23.

WVith the arrangement which I have described the frequency of the oscillations radiating circuit and when this storage circuit is detuned the supply of the high frequency oscillations to the radiating circuit may be substantially interrupted. The vacuum tube system, however, will continue to produce oscillations of the constant frequency and the energy of these oscillations will be absorbed in the storage circuit.

While I have shown and described a single embodiment of my invention it will be apparent that many modifications in the circuit arrangements employed may be made without departing from the scope of my invention as set forth in the appended. claims.

What I claim as new and desire to secure by Letters Patent of the United States, is

1. The combination of a vacuum tube generator of high frequency oscillations, a storage circuit to which high frequency oscillations are supplied, a radiating circuit which is supplied from said storage circuit and a direct connection from, said radiating circuit to the grid of the vacuum tube.

2. The combination of a vacuum tube generator of high frequency oscillations, a storage circuit to which high frequency oscillations are supplied, a radiating circuit which is supplied from said storage circuit and a connection from said radiating circuit to said generator for maintaining constant the frequency of the oscillation generated.

3. The combination of a vacuum tube generator of high frequency oscillations, a shortage circuit to which high frequency oscillations are supplied, a radiating circuit which is supplied from said storage circuit, a direct connection from said radiating circuit to the grid of the vacuum tube, and means for detuning the storage circuit and thereby interrupting the supply of oscillations to the radiating circuit.

4. The combination of a vacuum tube generator of high frequency oscillations, a storage circuit to which high frequency oscillations are supplied, a radiating circuit,

which is supplied from said storage circuit and means associated with the radiating circuit for maintaining substantially constant the frequency of the oscillations generated.

In witness whereof, I have hereunto set my hand this 5th day of November, 1923. WALTER R. G. BAKER.

Certificate of Correction.

It is hereby certified that in Letters Patent No. 1,518,682, granted December 9, 1924:, upon the application of Walter R. G. Baker, of Schenectady, New York, for an improvement in Signaling Systems, an error appears in the printed specification requiring correction as follows: Page 2, line 36, claim 3, for the Word shortage read storage; and that the said Letters Patent should beread with this correction therein that the same may conform to the record of the case in the Paternt Ofiice.

Signed and scaled this 27th day of January, A. D. 1925.

' [SEAL] KARL F ENN ING,

- Acting Commissioner of Patents. 

